NavList:

Gary I wrote: “That is the book I was looking for, except my version was hardback and fatter than that.  Does your version go on to describe a lot more about DR and celestial provision in US aircraft up to about 1939, or am I getting that mixed up with a different book by Rogers?”

I found the book I spoke of.  It was “Most Probable position” by Monte Duane Wright 1972.  It was stuffed at the bottom of a pile of books lying on their sides, because I foolishly ordered bookshelves online without checking the distance between shelves.  I note that it spent the first few years of its life in California State University, Northridge Library and still contained its punched card library ticket being used as a bookmark, so how it came to end up in the UK I’ve no idea.

I do recall looking at Precision Astrolabe, but I don’t have it at home.  I think it must have been one of several books I asked to see on a rushed visit the British Library some years ago.  DaveP